plugeth/les/odr.go
Felföldi Zsolt ca376ead88 les, light: LES/2 protocol version (#14970)
This PR implements the new LES protocol version extensions:

* new and more efficient Merkle proofs reply format (when replying to
  a multiple Merkle proofs request, we just send a single set of trie
  nodes containing all necessary nodes)
* BBT (BloomBitsTrie) works similarly to the existing CHT and contains
  the bloombits search data to speed up log searches
* GetTxStatusMsg returns the inclusion position or the
  pending/queued/unknown state of a transaction referenced by hash
* an optional signature of new block data (number/hash/td) can be
  included in AnnounceMsg to provide an option for "very light
  clients" (mobile/embedded devices) to skip expensive Ethash check
  and accept multiple signatures of somewhat trusted servers (still a
  lot better than trusting a single server completely and retrieving
  everything through RPC). The new client mode is not implemented in
  this PR, just the protocol extension.
2017-10-24 15:19:09 +02:00

119 lines
3.3 KiB
Go

// Copyright 2016 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package les
import (
"context"
"github.com/ethereum/go-ethereum/core"
"github.com/ethereum/go-ethereum/ethdb"
"github.com/ethereum/go-ethereum/light"
"github.com/ethereum/go-ethereum/log"
)
// LesOdr implements light.OdrBackend
type LesOdr struct {
db ethdb.Database
chtIndexer, bloomTrieIndexer, bloomIndexer *core.ChainIndexer
retriever *retrieveManager
stop chan struct{}
}
func NewLesOdr(db ethdb.Database, chtIndexer, bloomTrieIndexer, bloomIndexer *core.ChainIndexer, retriever *retrieveManager) *LesOdr {
return &LesOdr{
db: db,
chtIndexer: chtIndexer,
bloomTrieIndexer: bloomTrieIndexer,
bloomIndexer: bloomIndexer,
retriever: retriever,
stop: make(chan struct{}),
}
}
// Stop cancels all pending retrievals
func (odr *LesOdr) Stop() {
close(odr.stop)
}
// Database returns the backing database
func (odr *LesOdr) Database() ethdb.Database {
return odr.db
}
// ChtIndexer returns the CHT chain indexer
func (odr *LesOdr) ChtIndexer() *core.ChainIndexer {
return odr.chtIndexer
}
// BloomTrieIndexer returns the bloom trie chain indexer
func (odr *LesOdr) BloomTrieIndexer() *core.ChainIndexer {
return odr.bloomTrieIndexer
}
// BloomIndexer returns the bloombits chain indexer
func (odr *LesOdr) BloomIndexer() *core.ChainIndexer {
return odr.bloomIndexer
}
const (
MsgBlockBodies = iota
MsgCode
MsgReceipts
MsgProofsV1
MsgProofsV2
MsgHeaderProofs
MsgHelperTrieProofs
)
// Msg encodes a LES message that delivers reply data for a request
type Msg struct {
MsgType int
ReqID uint64
Obj interface{}
}
// Retrieve tries to fetch an object from the LES network.
// If the network retrieval was successful, it stores the object in local db.
func (odr *LesOdr) Retrieve(ctx context.Context, req light.OdrRequest) (err error) {
lreq := LesRequest(req)
reqID := genReqID()
rq := &distReq{
getCost: func(dp distPeer) uint64 {
return lreq.GetCost(dp.(*peer))
},
canSend: func(dp distPeer) bool {
p := dp.(*peer)
return lreq.CanSend(p)
},
request: func(dp distPeer) func() {
p := dp.(*peer)
cost := lreq.GetCost(p)
p.fcServer.QueueRequest(reqID, cost)
return func() { lreq.Request(reqID, p) }
},
}
if err = odr.retriever.retrieve(ctx, reqID, rq, func(p distPeer, msg *Msg) error { return lreq.Validate(odr.db, msg) }, odr.stop); err == nil {
// retrieved from network, store in db
req.StoreResult(odr.db)
} else {
log.Debug("Failed to retrieve data from network", "err", err)
}
return
}